One of every four women who gave birth in Fairfax County last year was not married, a sharp increase from 2007, when 9 percent were unmarried, according to new Census Bureau data. Across the Potomac, the percentage of unwed women giving birth in the demographically and economically similar Montgomery County dropped. Twelve percent were unmarried in 2010, compared with 20 percent in 2007.
In both counties, Hispanics made up proportionately more of the unmarried women giving birth.
| By the numbers | ||||
| 2010 2007 | ||||
| Montgomery | Fairfax | Montgomery | Fairfax | |
| Woman age 15-50 | ||||
| Hispanic | 47,609 | 48,713 | 35,894 | 36,553 |
| Non Hispanic | 199,543 | 232,447 | 200,166 | 219,091 |
| Woman age 15-50 who gave birth in the past year | ||||
| Hispanic | 2,710 | 2,703 | 2,143 | 2,290 |
| Non Hispanic | 9,268 | 12,748 | 11,046 | 9,840 |
| Unmarried woman age 15-50 who gave birth in the past year | ||||
| Hispanic | 381 | 952 | 482 | 138 |
| Non Hispanic | 1,105 | 2,858 | 2,191 | 959 |
| Source: US CENSUS BUREAU | ||||
In Fairfax, 17 percent of the county’s 281,160 women between the ages of 15 and 50,were Hispanic in 2010. However, Hispanics accounted for 25 percent of the unmarried women and 17.5 percent of the total women — married and unmarried — who gave birth.
As in Fairfax, 26 percent of the unmarried women who gave birth in 2010 in Montgomery were Hispanic, as were 22.6 percent of all women who gave birth that year. Hispanics made up only 19 percent of the women of child-bearing age that year.
Between 2007 and 2010, the number of women between 15 and 50 grew by just under 10 percent in Fairfax and just under 5 percent in Montgomery.
The Fairfax County data buck nationwide trends, experts say.
In a recession, fewer people have children, according to data from the Pew Research Center. However, in Fairfax the numbers have shown a sharp rise since the recession began.
Large changes of the type that Fairfax has seen in the last three years are unusual, according to George Washington University sociology professor Ivy Ken. She suggested that the changes may have been caused by a change in the types of programs offered by one or both of the counties or in the financial incentives that may encourage someone to have children.
Also, more women — and older women — are choosing to have children without getting married, according to New York’s Center for Human Reproduction.
Montgomery County Department of Health and Human Services spokeswoman Mary Anderson said she is unaware of any changes that may have inspired the decline in unmarried women having children.
Montgomery County Health Officer Ulder Tillman declined to comment, according to Anderson. Fairfax County officials did not return requests for comment.

